Pacemakers are classified depending on how many sections (chambers) of the heart they are able to stimulate - one, two or three.
Single-chamber devices are “classic” pacemakers that appeared earlier than others and have 1 electrode. They are installed in one chamber of the heart - the ventricle.
Two-chamber - have 2 electrodes that are implanted in the ventricle, atrium and support their synchronous operation. “Double” stimulation is more effective for the patient. If the patient has atrial fibrillation and flutter, dual-chamber pacemakers automatically switch to a safe mode of operation.
Three-chamber pacemakers are high-tech models with three electrodes that stimulate contractions of 3 heart chambers according to a certain sequence. Such devices are installed in patients with the most dangerous type of arrhythmia.
The electrodes of the devices are divided by fixation into active and passive types . In active fixation, the electrode is implanted inside the heart using a corkscrew attachment. Passively fixed electrodes are attached with special antennae.